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// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef TOOLS_GN_LABEL_PTR_H_
#define TOOLS_GN_LABEL_PTR_H_
#include <stddef.h>
#include <functional>
#include "tools/gn/label.h"
class Config;
class ParseNode;
class Target;
// Structure that holds a labeled "thing". This is used for various places
// where we need to store lists of targets or configs. We sometimes populate
// the pointers on another thread from where we compute the labels, so this
// structure lets us save them separately. This also allows us to store the
// location of the thing that added this dependency.
template<typename T>
struct LabelPtrPair {
typedef T DestType;
LabelPtrPair() : label(), ptr(nullptr), origin(nullptr) {}
explicit LabelPtrPair(const Label& l)
: label(l), ptr(nullptr), origin(nullptr) {}
// This contructor is typically used in unit tests, it extracts the label
// automatically from a given pointer.
explicit LabelPtrPair(const T* p)
: label(p->label()), ptr(p), origin(nullptr) {}
~LabelPtrPair() {}
Label label;
const T* ptr; // May be NULL.
// The origin of this dependency. This will be null for internally generated
// dependencies. This happens when a group is automatically expanded and that
// group's members are added to the target that depends on that group.
const ParseNode* origin;
};
typedef LabelPtrPair<Config> LabelConfigPair;
typedef LabelPtrPair<Target> LabelTargetPair;
typedef std::vector<LabelConfigPair> LabelConfigVector;
typedef std::vector<LabelTargetPair> LabelTargetVector;
// Comparison and search functions ---------------------------------------------
// To do a brute-force search by label:
// std::find_if(vect.begin(), vect.end(), LabelPtrLabelEquals<Config>(label));
template<typename T>
struct LabelPtrLabelEquals {
explicit LabelPtrLabelEquals(const Label& l) : label(l) {}
bool operator()(const LabelPtrPair<T>& arg) const {
return arg.label == label;
}
const Label& label;
};
// To do a brute-force search by object pointer:
// std::find_if(vect.begin(), vect.end(), LabelPtrPtrEquals<Config>(config));
template<typename T>
struct LabelPtrPtrEquals {
explicit LabelPtrPtrEquals(const T* p) : ptr(p) {}
bool operator()(const LabelPtrPair<T>& arg) const {
return arg.ptr == ptr;
}
const T* ptr;
};
// To sort by label:
// std::sort(vect.begin(), vect.end(), LabelPtrLabelLess<Config>());
template<typename T>
struct LabelPtrLabelLess {
bool operator()(const LabelPtrPair<T>& a, const LabelPtrPair<T>& b) const {
return a.label < b.label;
}
};
// Default comparison operators -----------------------------------------------
//
// The default hash and comparison operators operate on the label, which should
// always be valid, whereas the pointer is sometimes null.
template<typename T> inline bool operator==(const LabelPtrPair<T>& a,
const LabelPtrPair<T>& b) {
return a.label == b.label;
}
template<typename T> inline bool operator<(const LabelPtrPair<T>& a,
const LabelPtrPair<T>& b) {
return a.label < b.label;
}
namespace std {
template<typename T> struct hash< LabelPtrPair<T> > {
std::size_t operator()(const LabelPtrPair<T>& v) const {
hash<Label> h;
return h(v.label);
}
};
} // namespace std
#endif // TOOLS_GN_LABEL_PTR_H_